Current File : //usr/src/kernels/3.10.0-1160.83.1.el7.centos.plus.x86_64/include/linux/shm.h
#ifndef _LINUX_SHM_H_
#define _LINUX_SHM_H_
#include <asm/page.h>
#include <uapi/linux/shm.h>
#include <asm/shmparam.h>
struct shmid_kernel /* private to the kernel */
{
struct kern_ipc_perm shm_perm;
struct file *shm_file;
unsigned long shm_nattch;
unsigned long shm_segsz;
time_t shm_atim;
time_t shm_dtim;
time_t shm_ctim;
pid_t shm_cprid;
pid_t shm_lprid;
struct user_struct *mlock_user;
/* The task created the shm object. NULL if the task is dead. */
struct task_struct *shm_creator;
};
/* shm_mode upper byte flags */
#define SHM_DEST 01000 /* segment will be destroyed on last detach */
#define SHM_LOCKED 02000 /* segment will not be swapped */
#define SHM_HUGETLB 04000 /* segment will use huge TLB pages */
#define SHM_NORESERVE 010000 /* don't check for reservations */
/* Bits [26:31] are reserved */
/*
* When SHM_HUGETLB is set bits [26:31] encode the log2 of the huge page size.
* This gives us 6 bits, which is enough until someone invents 128 bit address
* spaces.
*
* Assume these are all power of twos.
* When 0 use the default page size.
*/
#define SHM_HUGE_SHIFT 26
#define SHM_HUGE_MASK 0x3f
#define SHM_HUGE_2MB (21 << SHM_HUGE_SHIFT)
#define SHM_HUGE_1GB (30 << SHM_HUGE_SHIFT)
#ifdef CONFIG_SYSVIPC
long do_shmat(int shmid, char __user *shmaddr, int shmflg, unsigned long *addr,
unsigned long shmlba);
extern int is_file_shm_hugepages(struct file *file);
extern void exit_shm(struct task_struct *task);
#else
static inline long do_shmat(int shmid, char __user *shmaddr,
int shmflg, unsigned long *addr,
unsigned long shmlba)
{
return -ENOSYS;
}
static inline int is_file_shm_hugepages(struct file *file)
{
return 0;
}
static inline void exit_shm(struct task_struct *task)
{
}
#endif
#endif /* _LINUX_SHM_H_ */
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